US12366620B2 - Split self-shielded gradient coil system, with power supply system for individually adjusting currents of sub-coil groups - Google Patents

Split self-shielded gradient coil system, with power supply system for individually adjusting currents of sub-coil groups

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US12366620B2
US12366620B2 US18/339,802 US202318339802A US12366620B2 US 12366620 B2 US12366620 B2 US 12366620B2 US 202318339802 A US202318339802 A US 202318339802A US 12366620 B2 US12366620 B2 US 12366620B2
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coil
sub
gradient
gradient coil
groups
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US20230417849A1 (en
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Silvia Buttazzoni
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Bruker Switzerland AG
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Bruker Switzerland AG
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/385—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using gradient magnetic field coils
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/32—Excitation or detection systems, e.g. using radio frequency signals
    • G01R33/36—Electrical details, e.g. matching or coupling of the coil to the receiver
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/385—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using gradient magnetic field coils
    • G01R33/3852—Gradient amplifiers; means for controlling the application of a gradient magnetic field to the sample, e.g. a gradient signal synthesizer
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/38—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field
    • G01R33/385—Systems for generation, homogenisation or stabilisation of the main or gradient magnetic field using gradient magnetic field coils
    • G01R33/3858—Manufacture and installation of gradient coils, means for providing mechanical support to parts of the gradient-coil assembly
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/28—Details of apparatus provided for in groups G01R33/44 - G01R33/64
    • G01R33/42—Screening
    • G01R33/421—Screening of main or gradient magnetic field
    • G01R33/4215—Screening of main or gradient magnetic field of the gradient magnetic field, e.g. using passive or active shielding of the gradient magnetic field
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01R—MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES
    • G01R33/00—Arrangements or instruments for measuring magnetic variables
    • G01R33/20—Arrangements or instruments for measuring magnetic variables involving magnetic resonance
    • G01R33/44—Arrangements or instruments for measuring magnetic variables involving magnetic resonance using nuclear magnetic resonance [NMR]
    • G01R33/48—NMR imaging systems
    • G01R33/54—Signal processing systems, e.g. using pulse sequences ; Generation or control of pulse sequences; Operator console
    • G01R33/56—Image enhancement or correction, e.g. subtraction or averaging techniques, e.g. improvement of signal-to-noise ratio and resolution
    • G01R33/565—Correction of image distortions, e.g. due to magnetic field inhomogeneities
    • G01R33/56518—Correction of image distortions, e.g. due to magnetic field inhomogeneities due to eddy currents, e.g. caused by switching of the gradient magnetic field

Definitions

  • NMR experiments typically apply pulse sequences wherein the gradient coil magnetic fields have to be switched rapidly. Then the electric current in the gradient coil system has to be switched on and off in a very short time, typically in the order of a few dozens of milliseconds. Further, gradient coil systems are required to provide strong magnetic fields within a limited space with low impact of eddy currents.
  • both the main coil is subdivided into a plurality of main sub-coils
  • the shielding coil is subdivided into a plurality of shielding sub-coils.
  • These sub-coils are allocated to a plurality of sub-coil groups, with each sub-coil group comprising one of the main sub-coils and one of the shielding sub-coils electrically connected in series.
  • the power supply system is capable of setting the electric current in each of the sub-coils individually.
  • the inductivity and resistance of each sub-coil and of each sub-coil group can be kept relatively small. Further, the coil sub-groups can be decoupled fairly easily, in particular by keeping a sufficient separation along the z axis and/or along the gradient direction x or y or z. Thus, time for charging and decharging the sub-coil groups can be kept small, and fast switching times are possible. At the same time, the generated fields of the sub-coil groups add up in the target volume, and thus the generation of strong gradient coil magnetic fields is possible in the target volume.
  • the respective main sub-coil and shielding sub-coil are typically located at basically the same position in z, and therefore a good shielding effect can be achieved for the respective sub-coil group.
  • Low inductivity and resistance are obtained both for the respective main sub-coils and also for the shielding sub-coils, contributing to fast switching times, too.
  • FIG. 5 b shows schematically a variant of the fourth embodiment of an inventive gradient coil system, comprising four sub-coil groups with non-uniform winding directions in some of the sub-coils (here: all main sub-coils and some shielding sub-coils), with a winding direction scheme.
  • FIG. 11 shows an exemplary design of a main coil for an inventive gradient coil system, for generating a gradient in y direction.
  • FIG. 14 shows a variant of the design of the main coil of FIG. 11 , with a different electric connection scheme as compared to FIG. 11 .
  • FIG. 15 shows a schematic cross-section of an exemplary NMR spectrometer for the invention.
  • M 6a6b of the two sub-coil groups 6 a , 6 b further M 6a6b ⁇ 0.05*L applies here, preferably with M 6a6b being practically zero.
  • the inductive decoupling can be accomplished by sufficient distance between the sub-coil groups 6 a , 6 b , in particular along the z direction.
  • FIG. 2 illustrates a schematic circuit diagram of a second embodiment of an inventive gradient coil system 1 , similar to the one shown in FIG. 1 , so only the major differences are explained below.
  • the power supply system 4 comprises a common power supply unit 7 , providing all sub-coil groups 6 a , 6 b with electric currents Ia, Ib in parallel.
  • the electric current Ia is directly supplied by and adjusted via the common power supply unit 7 .
  • the electric current Ib is adjusted (in addition to the adjustment at the common power supply unit 7 ) via a current adjustment unit 8 .
  • the current adjustment unit 8 may be designed as a variable resistor, for example.
  • the main sub-coil 2 a consists of six windings connected in series (note that in the top part the windings are individually shown for simplification), all of which have a uniform winding direction (illustrated with arrow upwards in the bottom part).
  • the winding direction corresponds to the electric current direction in the winding (clockwise or counter clockwise) when in each case looking in a fixedly defined way with respect to the coil axis (e.g. along the z axis in each case, or against the z axis in each case).
  • the main sub-coil 2 b consists of six windings connected in series, all of which have a uniform winding direction (illustrated with arrow downwards in the bottom part).
  • the shielding sub-coil 3 b consists here of six windings connected in series, all of which have a uniform winding direction (illustrated with arrow upwards in the bottom part).
  • the axial position in z of the main sub-coil 2 b and the shielding sub-coil 3 b are basically the same.
  • the main sub-coils 2 a , 2 b have a uniform radius here, and the shielding sub-coils 3 a , 3 b have a uniform radius here.
  • the radius of the shielding sub-coils 3 a , 3 b is larger than the radius of the main sub-coils, here about twice as large.
  • the center 9 of the target volume 10 of the gradient coil system 1 is also the magnetic center of the gradient coil 5 altogether.
  • the windings of the sub-coil groups 6 a , 6 b are arranged mirror-symmetric with respect to a mirror plane M perpendicular to the z axis and including the center point 9 (neglecting the electric supply lines and the winding directions).
  • the target volume 10 is here basically cylindrical (with the cylinder axis along the z axis) and is somewhat elongated in the z direction, what is particularly useful for a sample in a vial or sample tube. Note that the target volume 10 may extend into the axial interior of the main sub-coils 2 a , 2 b.
  • the sub-coils 2 a , 3 a of sub-coil group 6 a are connected in series and receive power from power supply unit 4 a via connecting cables 11
  • sub-coils 2 b , 3 b of sub-coil group 6 b are connected in series and receive power from power supply unit 4 b via connecting cables 11 .
  • the connecting cables (supply lines) 11 lead from the sub-coil groups 6 a , 6 b to one axial side of the gradient coil 5 only, for example to the left axial side, for connecting to the power supply system or here its power supply units 6 a , 6 b , respectively, so the other axial side is free for a sample supply systems (not shown here, but compare FIG. 15 ).
  • FIG. 4 illustrates a third embodiment of a gradient coil system 1 , similar to the embodiment shown in FIG. 3 , so only the major differences are explained below.
  • FIG. 5 a shows a fourth embodiment of an inventive gradient coil system 1 similar to the gradient coil system shown in FIG. 4 , wherein only the winding direction scheme is illustrated in FIG. 5 a . Only the major differences are explained below.
  • the winding direction in some sub-coils, here in main sub-coils 2 a and 2 d changes within the respective sub-coil.
  • the majority of the windings (here the axial outer windings) has winding direction “upwards” in main sub-coil 2 a and “downwards” in main-sub coil 2 d
  • the minority of windings (here the axial inner winding) has winding direction “downwards” in main sub-coil 2 a and “upwards” in main sub-coil 2 d
  • the winding direction is “downwards” and therefore uniform and opposite to the majority of windings of main sub-coil 2 a .
  • the winding direction in some sub-coils here in all main sub-coils 2 a , 2 b , 2 c , 2 d and in the axially inner shielding sub-coils 3 b , 3 c , changes within the respective sub-coil.
  • the respective axially inner winding has an opposite winding direction as compared to the respective axially outer windings.
  • FIG. 6 illustrates schematically a fifth embodiment of an inventive gradient coil system 1 in a geometric scheme, wherein the main coil 2 (top) and the shielding coil 3 (bottom) are shown separated for better understanding. Note that the main coil 2 and the shielding coil 3 are coaxial with respect to the z axis.
  • the gradient coil system 1 comprises two sub-coil groups 6 a (with sub-coils 2 a , 3 a ) and 6 b (with sub-coils 2 b , 3 b ).
  • the main sub-coil 2 b is most of its part mirror-symmetric to main sub-coil 2 a with respect to mirror plane M, but main sub-coil 2 b contains an additional winding package 12 , for which there is no equivalent in main sub-coil 2 a .
  • the shielding sub-coil 3 a is most of its part mirror-symmetric to shielding sub-coil 3 b with respect to mirror plane M, but shielding sub-coil 3 a contains an additional winding 13 , for which there is no equivalent in shielding sub-coil 3 b . So, in the example shown in FIG. 6 , the sub-coil groups 6 a , 6 b are arranged asymmetric with respect to the mirror plane M (which runs perpendicular to the central z axis and cuts the center point of the gradient coil).
  • FIG. 6 by way of example, there is also illustrated the measurement of a target volume profile of a gradient coil system 1 by inserting and moving a Hall probe 21 , typically arranged on a holder 22 , into the main coil 2 along the z axis.
  • the gradient coil system 1 is operated with constant currents, and the gradient coil magnetic field is measured as a function of the z position.
  • the pick-up loop 20 has a radius c larger than the (maximum) radius b of the gradient coil system 1 , and the pick-up loop 20 is arranged in a plane perpendicular to the z axis.
  • the gradient coil system 1 is operated with alternating currents, and an induced electric voltage in the pick-up loop 20 is measured as a function of the z position.
  • FIG. 7 illustrates an exemplary diagram showing residual magnetic flux profiles (flux shown on the ordinate/upward axis) along the z direction (z position shown on the abscissa/rightward axis) of a typical gradient coil system in accordance with the invention, for example as shown in FIG. 1 .
  • the residual magnetic flux is measured in a plane perpendicular to the z axis and within a radius c, which is larger than the (maximum) radius b of the gradient coil system, for example with a pick-up loop of radius c with an alternating current in the sub-coil groups (not shown, but compare FIG. 6 ).
  • the diagram shows in solid lines a desired residual profile 14 a (or reference residual profile, “reference flux”) which would result for an ideal gradient coil system, without manufacturing tolerances (and optionally also taking into account influence from an NMR probe or other magnet components), for which the influence of eddy currents on the NMR measurement would be minimal.
  • the desired residual profile 14 a is typically calculated based on the overall design of the NMR probe.
  • a measured residual profile 14 b is obtained which is distorted with respect to the reference residual profile (“distorted flux”).
  • the measured residual profile 14 b is shown with dotted lines, note that for most of it, it is overlaid by the reference residual profile 14 a .
  • the measured residual profile 14 b deviates from an antisymmetric profile, and is therefore considered asymmetric.
  • the measured residual profile 14 b can be adjusted and brought close to the reference residual profile 14 a , or the measured residual profile 14 b can be made (approximately) anti-symmetric with respect to the center 9 .
  • different current settings may be set and the residual profile 14 b may be measured again, thus adjusting the measured residual profile 14 b iteratively.
  • a typical current difference between two sub-coil groups is typically up to 6%, preferably up to 4% with respect to the lower current, in order to achieve an antisymmetric measured residual profile.
  • FIG. 8 illustrates exemplary, typical NMR signals (obtained by fast Fourier transformation of free induction decay, with signal amplitude noted on the ordinate/upward axis, and frequency ⁇ noted to the abscissa/rightward axis) obtained with a distorted residual (flux) profile (see FIG. 7 ), compare the distorted signal 15 shown in dashed lines, and a reference signal 16 obtained with the reference residual (flux) profile (see FIG. 7 ) shown in solid lines.
  • the distorted residual profile causes a phase artifact in NMR measurements, as can be seen in the measured distorted signal 15 .
  • the exemplary diagram of FIG. 9 shows profiles of the first derivative dBz/dz (noted on the ordinate/upward axis) of the gradient coil magnetic field Bz as a function of the position along z (noted to the abscissa/rightward axis) in the target volume for a typical gradient coil system according to the invention, for example as shown in FIG. 1 .
  • a reference target volume profile also called desired target volume profile 17
  • a measured target volume profile 18 in general deviates from the desired target volume profile 17 , i.e., the measured target volume 18 profile is distorted with respect to the desired target volume profile 17 .
  • the measured target volume profile 18 can be adjusted and brought close to the desired target volume profile 17 , or the measured target volume profile 18 can be (approximately) made symmetric with respect to the center 9 . This improves the NMR measurement quality, in particular the resolution.
  • a typical current difference between two sub-coil groups is typically up to 6%, preferably up to 4% with respect to the lower current, in order to achieve an symmetric target volume profile.
  • FIG. 10 shows in a schematic perspective view a main gradient coil 2 for the present invention, for generating an x gradient of the gradient coil magnetic field Bz.
  • the main gradient coil 2 comprises a first main sub-coil 2 a (on the right side of the coil bobbin, with respect to the circumference), and a second main sub-coil 2 b (on the left side of the coil bobbin).
  • the main sub-coils 2 a , 2 b are arranged opposite to each other with respect to the x direction.
  • the corresponding shielding coil may be designed analogously, but with a larger radius.
  • FIG. 11 shows in a schematic perspective view a main gradient coil 2 for the present invention, for generating a y gradient of the gradient coil magnetic field Bz.
  • the main gradient coil 2 comprises a first main sub-coil 2 a (on the top side of the coil bobbin, with respect to the circumference), and a second main sub-coil 2 b (on the bottom side of the coil bobbin).
  • the main sub-coils 2 a , 2 b are arranged opposite to each other with respect to the y direction.
  • the corresponding shielding coil may be designed analogously, but with a larger radius.
  • FIG. 12 shows in a schematic perspective view a main gradient coil 2 for the present invention, for generating a z gradient of the gradient coil magnetic field Bz.
  • the main gradient coil 2 comprises four main sub-coils 2 a - 2 d , basically running circular about the bobbin each.
  • the main sub-coils 2 a - 2 d are arranged subsequently along the z axis. Note that the corresponding shielding coil may be designed analogously, but with a larger radius.
  • gradient coil systems as sketched in FIGS. 10 - 12 may be radially nested (not shown). Further note that x, y, z form an orthogonal coordinate system.
  • FIG. 13 shows in a schematic perspective view a main gradient coil 2 for the present invention, for generating an x gradient of the gradient coil magnetic field Bz, similar to the design shown in FIG. 10 . Only the major differences are explained.
  • the main gradient coil 2 comprises a first main sub-coil 2 a (on the left axial side of the coil bobbin), and a second main sub-coil 2 b (on the right axial side of the coil bobbin).
  • the main sub-coils 2 a , 2 b are arranged opposite to each other with respect to the z direction.
  • the corresponding shielding coil may be designed analogously, but with a larger radius.
  • FIG. 14 shows in a schematic perspective view a main gradient coil 2 for the present invention, for generating a y gradient of the gradient coil magnetic field Bz, similar to the design shown in FIG. 11 . Only the major differences are explained.
  • the main gradient coil 2 comprises a first main sub-coil 2 a (on the right axial side of the coil bobbin), and a second main sub-coil 2 b (on the left axial side of the coil bobbin).
  • the main sub-coils 2 a , 2 b are arranged opposite to each other with respect to the z direction.
  • the corresponding shielding coil may be designed analogously, but with a larger radius.
  • FIG. 15 shows in a very schematic cross-section an NMR spectrometer 30 for the invention, comprising a cryostat 31 with a room temperature bore 32 running parallel to a z axis.
  • the cryostat 31 contains a superconducting magnet 37 , generating a background magnetic field B 0 along the z axis in a target volume 10 inside the bore 32 .
  • a gradient coil system 1 for generating (here) a gradient coil magnetic field varying along the z (and/or x, y) axis.
  • the gradient coil system 1 is supplied with electric currents by a power supply system 4 via electric connecting cables 11 , all of which lead downwards from the gradient coil system 1 .
  • the power supply system 4 here comprises two individual power supply units for powering two sub-coil groups.
  • a ⁇ Grad , c ( x ⁇ , t ) ⁇ 0 4 ⁇ ⁇ ⁇ ⁇ V j ⁇ Grad ( y ⁇ , t ) ⁇ " ⁇ [LeftBracketingBar]" x ⁇ - y ⁇ ⁇ " ⁇ [RightBracketingBar]” ⁇ d 3 ⁇ y
  • V is the measuring volume
  • ⁇ right arrow over (A) ⁇ Soll,c is the desired vector potential, which is generated by non-vanishing outer residual fields.
  • ⁇ right arrow over (A) ⁇ Soll,c is determined during the design of the gradient coil system and is generated by discretion of currents both in the main coil and in the shielding coil, and by the limited space in z direction.
  • This vector potential is already optimized with respect to effects of induced eddy currents on the NMR signal, flowing after switching of the current in the gradient coil system.
  • ⁇ right arrow over (A) ⁇ Ist,c is the actual vector potential on the same cylinder tube.
  • the vectors ⁇ right arrow over (e) ⁇ ⁇ and ⁇ right arrow over (e) ⁇ z are the unit vectors in cylinder coordinates.
  • the Fourier transforms are calculated as follows
  • the induced voltage can be measured in a simple way.

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  • Condensed Matter Physics & Semiconductors (AREA)
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US18/339,802 2022-06-24 2023-06-22 Split self-shielded gradient coil system, with power supply system for individually adjusting currents of sub-coil groups Active 2043-10-12 US12366620B2 (en)

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EP22181052.6A EP4296702A1 (fr) 2022-06-24 2022-06-24 Système de bobines de gradient auto-blindées divisées doté d'un système d'alimentation permettant de régler individuellement les courants des groupes de sous-bobines
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Citations (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0136536A2 (fr) * 1983-09-06 1985-04-10 General Electric Company Bobine à gradient de champ magnétique axial utilisée dans un appareil à résonance magnétique nucléaire
WO1998003887A1 (fr) * 1996-07-23 1998-01-29 British Technology Group Usa, Inc. Bobines a gradient resonnantes pour irm
JPH10179544A (ja) 1996-12-20 1998-07-07 Shimadzu Corp Ｍｒ装置の傾斜磁場発生用コイル
US5867027A (en) * 1995-07-27 1999-02-02 Kabushiki Kaisha Toshiba Magnetic resonance imaging apparatus
US6313630B1 (en) 1999-08-25 2001-11-06 Ge Medical Systems Global Technology Company Llc Modular gradient system for MRI system
US7230426B2 (en) 2003-06-20 2007-06-12 General Electric Company Split-shield gradient coil with improved fringe-field
US20090315560A1 (en) * 2008-06-20 2009-12-24 Irving Weinberg Apparatus and method for decreasing bio-effects of magnetic gradient field gradients
JP2010179544A (ja) 2009-02-05 2010-08-19 Seiko Epson Corp 流体吐出装置及びその制御方法
US20130229182A1 (en) 2012-03-02 2013-09-05 Bruker Biospin Ag Gradient coil with correction windings and method for production thereof
US20140176138A1 (en) * 2011-09-05 2014-06-26 Hitachi Medical Corporation Gradient magnetic field coil device, adjustment method therefor, and magnetic resonance imaging apparatus
CN104020429A (zh) 2014-06-06 2014-09-03 南京工程学院 一种梯度线圈并联分层的布线结构和布线方法
CN204009031U (zh) 2014-06-03 2014-12-10 南京工程学院 一种有源屏蔽梯度线圈结构
EP2910965A1 (fr) 2014-02-19 2015-08-26 Albert-Ludwigs-Universität Freiburg Système de commutation multicanaux pour bobines à gradient de matrice IRM
CN204649944U (zh) 2015-05-27 2015-09-16 上海辰光医疗科技股份有限公司 指关节射频线圈
CN204649947U (zh) 2015-06-10 2015-09-16 武汉中科波谱技术有限公司 一种核磁共振波谱仪梯度线圈
US20160334480A1 (en) 2015-05-12 2016-11-17 Albert-Ludwigs-Universitat Freiburg Arrangement for modifying a main magnetic field and method for producing such an arrangement
CN107957565A (zh) 2017-12-21 2018-04-24 武汉中科牛津波谱技术有限公司 一种核磁共振波谱仪自屏蔽梯度线圈及其设计方法
US20220034983A1 (en) * 2020-07-29 2022-02-03 Synaptive Medical Inc. System and method to improve performance of asymmetrical gradient coils by allowing a uniform offset field
CN114545312A (zh) 2022-04-22 2022-05-27 浙江浙大西投脑机智能科技有限公司 一种非线性梯度线圈及扫描方法

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8511390B2 (en) 2009-12-23 2013-08-20 Bp Corporation North America Inc. Rigless low volume pump system

Patent Citations (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0136536A2 (fr) * 1983-09-06 1985-04-10 General Electric Company Bobine à gradient de champ magnétique axial utilisée dans un appareil à résonance magnétique nucléaire
US5867027A (en) * 1995-07-27 1999-02-02 Kabushiki Kaisha Toshiba Magnetic resonance imaging apparatus
WO1998003887A1 (fr) * 1996-07-23 1998-01-29 British Technology Group Usa, Inc. Bobines a gradient resonnantes pour irm
JPH10179544A (ja) 1996-12-20 1998-07-07 Shimadzu Corp Ｍｒ装置の傾斜磁場発生用コイル
US6313630B1 (en) 1999-08-25 2001-11-06 Ge Medical Systems Global Technology Company Llc Modular gradient system for MRI system
US7230426B2 (en) 2003-06-20 2007-06-12 General Electric Company Split-shield gradient coil with improved fringe-field
US20090315560A1 (en) * 2008-06-20 2009-12-24 Irving Weinberg Apparatus and method for decreasing bio-effects of magnetic gradient field gradients
JP2010179544A (ja) 2009-02-05 2010-08-19 Seiko Epson Corp 流体吐出装置及びその制御方法
US20140176138A1 (en) * 2011-09-05 2014-06-26 Hitachi Medical Corporation Gradient magnetic field coil device, adjustment method therefor, and magnetic resonance imaging apparatus
US20130229182A1 (en) 2012-03-02 2013-09-05 Bruker Biospin Ag Gradient coil with correction windings and method for production thereof
EP2910965A1 (fr) 2014-02-19 2015-08-26 Albert-Ludwigs-Universität Freiburg Système de commutation multicanaux pour bobines à gradient de matrice IRM
CN204009031U (zh) 2014-06-03 2014-12-10 南京工程学院 一种有源屏蔽梯度线圈结构
CN104020429A (zh) 2014-06-06 2014-09-03 南京工程学院 一种梯度线圈并联分层的布线结构和布线方法
US20160334480A1 (en) 2015-05-12 2016-11-17 Albert-Ludwigs-Universitat Freiburg Arrangement for modifying a main magnetic field and method for producing such an arrangement
US10234520B2 (en) 2015-05-12 2019-03-19 Albert-Ludwigs-Universität Freiburg Arrangement for modifying a main magnetic field and method for producing such an arrangement
CN204649944U (zh) 2015-05-27 2015-09-16 上海辰光医疗科技股份有限公司 指关节射频线圈
CN204649947U (zh) 2015-06-10 2015-09-16 武汉中科波谱技术有限公司 一种核磁共振波谱仪梯度线圈
CN107957565A (zh) 2017-12-21 2018-04-24 武汉中科牛津波谱技术有限公司 一种核磁共振波谱仪自屏蔽梯度线圈及其设计方法
US20220034983A1 (en) * 2020-07-29 2022-02-03 Synaptive Medical Inc. System and method to improve performance of asymmetrical gradient coils by allowing a uniform offset field
CN114545312A (zh) 2022-04-22 2022-05-27 浙江浙大西投脑机智能科技有限公司 一种非线性梯度线圈及扫描方法

Non-Patent Citations (4)

* Cited by examiner, † Cited by third party
Title
Littin et al., Development and implementation of an 84-Channel Matrix Gradient Coil, Magnetic Resonance in Medicine 79:1181-1191, 2018.
Questions and Answers in MRI, Z-Gradients, available at https://mriquestions.com/how-do-z-gradients-work.html#/ on May 18, 2022 (Year: 2022). *
T. Parella, "Pulsed field gradients: a new tool for routine NMR", Magnetic Resonance in Chemistry, vol. 36, No. 7 (Jul. 1998), pp. 467-495.
Textbook J. Cavanagh et al., "Protein NMR spectroscopy—principles and practice", Second edition (2006), Academic press, compare pp. 311-315 and pp. 574-578.

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